The invention relates to a tape for mass-sealing bottles and containers, as claimed in the preamble of claim 1, to an apparatus for applying said tape, and to an apparatus for removing the tape from bottles or containers as disclosed in the preamble of claim 10 and of claim 16, and in an apparatus for unsealing them.
Automatic lines for packaging liquid or solid products (generally but non necessarily foodstuffs) are well known, diffused, and extensively used in industry and (therefore) will not be described herein. However, in these lines, the containers (particularly for food contact packaging) must (or at least should) be washed and/or sterilized (or anyway accurately cleaned) before being filled: therefore, at the start of the packaging line, there is normally provided at least one washing step to clear the inside of containers of dust and/or other foreign matters, which may have penetrated them.
Well-known washing steps are normally able to accomplish the task wherefore they are designed and implemented but they may (or might) exceptionally fail, with harmful effects (at least in terms of commercial impact and/or image) for product packagers and vendors; as an example, one might think of a pack (of a food or non food product), inside which a purchaser/user would find a foreign body, like (for example) a mouse, a lizard and/or one or more bugs.
The jets of fluid under pressure (air and/or water), used in many well-known washing steps are not (or may not be) able to remove these foreign bodies, from the inside of a container, when they are large, or anyway as large as the mouth of the container.
To this end, the expedient of applying a seal, made of a film of extensible material, is known from the application for international patent PCT No. WO96/23702.
WO96/23702 discloses a device for sealing container openings, which permits to apply a stretch plastic film onto the openings to be sealed. Said device comprises a support, preferably flat-shaped, having at least one hole, on which is placed the stretch plastic film. Said film is held taut and adherent to the support by means of gluing, magnetic force, pressure, a counter pattern or in any other way. The device can bear marks or recognition messages, as well as a warning or an advertisement and can also be used for temporary sealing of containers.
Relating to apparati for applying the seal, WO/03478 discloses an apparatus for covering articles with a film, comprising means for relatively moving a sheet of film toward a primary surface of an article. Said sheet and said primary surface are generally parallel to one another. The article shows a secondary surface substantially perpendicular to said primary surface. The said means for moving have an extent of sufficient length to move said film towards and past said primary surface and along said secondary surface. Furthermore the apparti comprises means for circumferentially restraining said film in a plane substantially parallel to said primary surface, whereby said means for restraining causes said film to stretch as said means for relatively moving passes said primary surface.
Also document U.S. Pat. No. 3,112,587 discloses an apparatus for closing and sealing the mouth of a container. The apparatus disclosed is an apparatus for aspplying a sheet of heat sealable material to the mouth of a container comprising a heat sealing head, menas for advancing a sheet of heat sealable material past the sealing head, means for selectively clamping the sheet of material around a central mouth spanning area, means for moving the head, the sheet material and the container relative to each other, to bring the head and the mouth of the container into engagement with opposite sides of the mouth spanning portion of the sheet whereby to heat seal the same thereto, and means for thereafter moving the head and the container in unison relative to the clamping means with the head and container in engagement with opposite sides of the sheet to separate the mouth spanning portion from the sheet. The relative motion of the clamping means, of the head and of the bottle is achieved by actively displacing each of this parts.
Document U.S. Pat. No. 4,338,767 discloses a device for removing pressure sensitive sealing tape from a container. The apparatus has a seal removal station which is positioned along a bottle conveyor line upstream of a filling operation. In the said removal station oversized adhesive seals covering the mouth of the plastic bottles and adhering to the annular edge delimiting the mouth of the bottle are lifted off each bottle and transferred to a collector bin. Vacuum pressure generated in a plenum chamber formed in a stator member is transmitted to the nonadhesive upper surface of each seal through a perforated rotor surface rotating beneath the stator. Air jet means directing fluid pressure upward against marginal portions of each seal overlapping marginal portions of each seal and guide surfaces to flatten out curled portions of the seal are utilized to assure seal lift off by virtue of fluid pressure differentials.
DE-U-296 13 476 discloses a device for unsealing bottles having crown sealings and a film covering the crown sealing and the neck of the bottle. The device having mechanical scratching means for detaching from the neck covering sheets of paper, plastic or tinfoil.
The invention is based on the problem to improve the operations of sealing and unsealing bottles or containers, before they are filled and closed in a packaging line, in such a way that these operations may be mass-implemented, in a specific line, or a part of line upstream from the line for filling and closing the containers, the whole in a simple and cheap way, both as regards the material in use, and the construction of the line, and allowing for a reduced environmental impact.
The invention achieves the above purposes by providing a composite laminar tape, for mass-sealing bottles or similar containers.
The tape made of extensible film may be interposed between two support tapes having coincident holes and adhering against each other, by adhesives, embossing or other means, along longitudinal lateral stripes, outside the longitudinal lateral edges of the intervening film tape. Alternatively, the extensible film may be made to adhere to the support tape by directly gluing it thereto.
Advantageously, the extensible film weakening areas or predetermined tear-off lines, extending along closed lines, and along the edges of the holes in the support tape/s.
The invention also relates to an apparatus for mass-applying the sealing film on the mouth of bottles or similar containers, which uses a tape as described hereinbefore.
Here also, there are provided several possible embodiments, which form the subject of the following description and of the dependent claims.
The rigid element, having one surface provided with a hole, has associated means for feeding the tape, unwound from the coil, and for carrying it to an interposed position between the rigid element, i.e. its surface provided with a hole, and the opening of the container, said position being such that each hole of the support tape is sequentially carried coaxially to the hole in the rigid element.
Advantageously, downstream from the rigid element, there is provided a coil for recovering the tape once the part of film applied as a seal on the opening of the container, has been removed.
The invention also relates to an apparatus for unsealing containers.
In a preferred embodiment, the apparatus according to the invention further comprises rotation means, which set the operating head in a rotary motion with respect to the container (or vice versa) and/or separating means, placed inside the cavity of the operating head, which partially remove the seal, by separating its edge from the outer wall of the container and by lifting it up; the seal, partially removed by the separating means, is completely removed by the suction means.
Further improvements and possible variants in construction of the laminar tape, of the apparati for the application and removal of the seal on and from the containers will form the subject of the dependent claims.